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Biomedical subjects

W B Schwerk

Publications and source records attributed to W B Schwerk.

At least 19 recordsLinked to original sources
PubMed2000

[Ultrasound first in acute appendix? Unnecessary laparotomies can often be avoided].

Acute appendicitis is one of the most common causes of acute abdomen. Prospective studies have shown the overall accuracy of the clinical diagnosis to be not more than 70-78% in suspected appendicitis, with a correspondingly high rate of 20-25% unnecessary laparotomies. High-resolution ultrasonography (US) is a readily available, radiation-free noninvasive diagnostic modality that enables visualization of the inflamed appendix and a variety of relevant diseases in the differential diagnostic work-up. Prospective studies have shown that the overall accuracy of US in acute appendicitis ranges between 86 and 87% (sensitivity 75-92%, specificity 92-100%), with positive and negative predictive values of 89-96%, respectively. In experienced hands, US has significantly improved the diagnostic accuracy in suspected appendicitis, while halving the negative laparotomy rate to 8-15%. Since, however, a low percentage of false-negative US explorations due, for example, to accumulation of bowel gas or obesity, final therapeutic decisions be based on a careful consideration of US findings together with history, symptoms and clinical findings.

Abdomen, Acute↗
PubMed1999

[Intrarenal doppler flow analysis in patients with kidney transplantation and stable transplant function].

AIM OF THE STUDY: Intrarenal arterial Doppler sonography is used in noninvasive monitoring of transplant kidneys with controversial results. With the application of the method on renal transplants with stable function normal values should be generated and pitfalls should be identified. METHOD AND STUDY SUBJECTS: In a prospective study doppler findings in 61 renal transplant patients with stable graft function were compared with measurements in native kidneys of 60 healthy controls. In all kidneys duplex Doppler studies of arcuate/interlobar intrarenal arteries were performed and both the resistance index (RI) as well as the pulsatility index (PI) was determined. RESULTS: The results of our study are summarized: 1. Transplanted kidneys have significantly higher intrarenal arterial flow indices in comparison to native kidneys: RI = 67 +/- 5% in allografts vs. RI = 57 +/- 5% in native kidneys; and PI = 123 +/- 21% in allografts vs. PI = 91 +/- 15% in native kidneys, respectively. 2. RI and PI increase with age in both the native kidneys and the allografts. However, the increase in the transplanted kidney correlates with the age of the recipient but not with the age of the donor. 3. Corresponding to the increase in RI and PI the blood pressure is significantly elevated in the elderly. 4. The degree of external pressure with the transducer on the graft has an impact on the intrarenal arterial Doppler findings and measurements obtained. CONCLUSION: The intrarenal arterial Doppler findings dependent on various extrarenal factors. Using arterial Doppler sonography to evaluate transplant kidneys it is mandatory to take into account factors such as recipient's age and hemodynamic situation. External pressure with the transducer on the graft must be avoided. Once these factors were considered the intrarenal arterial Doppler sonography of kidney transplant is a valuable diagnostic tool.

Adult↗
PubMed1998

[Fatal pulmonary embolism after endoscopic embolization of downhill esophageal varix].

HISTORY AND CLINICAL FINDINGS: A 79-year-old man was admitted with a history of recent haematemesis and tarry stools. 4 years before he had undergone a subtotal thyroidectomy for hyperthyroidism. INVESTIGATIONS: He was anaemic (haemoglobin 7.2 g/dl, haematocrit 23%). At the transition between the upper and middle third of the oesophagus gastroscopy revealed a bleeding oesophageal varix. TREATMENT AND COURSE: The bleeding varix was sclerosed with polidocanol. 3 erythrocyte concentrates were administered. Massive bleeding 2 days later was controlled with intravaricose injection of cyanoacrylate (Histoacryl). The patient died 6 weeks later from progressive cardiovascular failure. Autopsy revealed the cause of death as right heart failure with extensive foreign-body pulmonary emboli identified as thrombotic material containing polymerized cyanoacrylate found in the previously injected oesophageal varix. Also discovered was a retrosternal goitre which had compressed the brachiocephalic vein. Cause of the "washing-out" of the cyanoacrylate embolus from the varix into the systemic circulation was an oesophago-varicose collateral circulation in a cranio-caudal direction; this had been formed by the pressure of the retrosternal goitre on the brachiocephalic vein. CONCLUSION: Cyanoacrylate injection into a varix above the lower third of the oesophagus should only be done under strict indication. A similar risk as that described in this case potentially exists in the treatment of acute bleeding from a portosystemic varicose circulation.

Aged↗
PubMed1997

Sonography of malignant pleural effusion.

Two hundred and ten patients with exudative pleural effusion were studied by ultrasound for sonographic signs of pleural carcinomatosis. Images were evaluated for echoes within the fluid, septations, sheet-like or nodular pleural masses, and associated lesions of the lung. Our results showed that sonographic findings of echogenic or septated fluid were unspecific for malignancy. Only the evidence of pleural masses was characteristic of malignant effusion. Ultrasound of the chest should therefore be carried out before invasive diagnostic procedures are planned.

Aged↗
PubMed1997

Malignant splenic lymphoma: sonographic patterns, diagnosis and follow-up.

UNLABELLED: Six hundred and eighty patients with malignant lymphoma were studied by abdominal sonography during 1983 and 1993 at our institution. Abnormal splenic texture was noted in 101 patients (14,8%). Involvement of the spleen was confirmed histologically (n = 8), by sonographic follow-up (n = 82), and on the basis of the clinical course in the remaining patients. Of the 101 patients with splenic involvement, 34 had Hodgkin's disease, 38 had a low-grade non-Hodgkin's lymphoma and 29 a high-grade non-Hodgkin's lymphoma. Four different sonographic patterns were observed: (1) Diffuse involvement in 37 patients (pts) (36.6%). (2) Focal small nodular lesions in 39 pts (38.6%). (3) Focal large nodular lesions in 23 pts (22,7%). (4) 'Bulky, disease' in two pts (1.9%). All of the high-grade lymphomas showed either large nodular (15/29) or small nodular (14/29) lesions. The diffuse or small nodular pattern was seen predominantly in low-grade lymphomas (35/38) and in Hodgkin's disease (31/34). CONCLUSION: A number of different patterns of splenic involvement in lymphoma can be demonstrated by ultrasound. Splenic sonographic patterns can be linked to histological lymphoma entities.

Adolescent↗
PubMed1996

Sonographic patterns in extranodal abdominal lymphomas.

Between 1980 and 1993, 680 patients with non-Hodgkin's lymphomas (NHL) and Hodgkin's disease (HD) were studied by ultrasonography. In 210 patients a total of 254 extranodular abdominal lymphoma infiltrates were diagnosed. Infiltrates were confirmed histologically in 118 patients and through the clinical course and follow-up studies in 92 patients. Lymphoma infiltrates were seen most frequently in the spleen (n = 101), the gastrointestinal tract (n = 70), the liver (n = 47), the kidneys (n = 17) and other organs (n = 19). The sonographic features of lymphomatous infiltrates in different extranodal sites are described, and possible correlations between lymphoma subtypes and sonographic texture characteristics are investigated. Different infiltration patterns of lymphoma subtypes could be identified in liver and spleen. High-grade NHLs most frequently showed large-nodular lesions, whereas low-grade NHLs and HD showed a tendency towards small-nodular or diffuse lesions. The role of ultrasonography in the clinical management of lymphoma patients is discussed.

Abdominal Neoplasms↗
PubMed1996

[Value of ultrasound in diagnosis of acute appendicitis].

Acute appendicitis is one of the most frequent causes of an acute abdomen. The clinical diagnosis is based on the case history and the physical examination which plays a major role in clinical diagnosis. However, in some cases the typical clinical symptoms are equivocal or misleading. Without using the opportunities of diagnostic imaging the accuracy of preoperative appendix diagnosis ranged between 70 and 78%. Consequently the rate of unnecessary laporotomies ranged between 22 and 28%. Since 1986, 13 studies including more than 5,000 patients have been published showing a sensitivity of 85% and a specificity of 96% if the sonographic examination was performed by an experienced examiner. The rate of negative laparotomies could be decreased to 7%, and possible differential diagnoses could be either confirmed or ruled out by using ultrasound technique. Based on the current literature, real-time sonography plays a major part in the diagnosis of acute appendicitis.

Abdomen, Acute↗
PubMed1996

Prospective evaluation of different diagnostic techniques for the detection of liver metastases at the time of primary resection of colorectal carcinoma.

OBJECTIVE: To evaluate preoperative and operative methods of detecting liver metastases in patients undergoing primary resection for colorectal carcinoma. DESIGN: Prospective, open study. SETTING: Teaching hospital, Germany. SUBJECTS: 51 Patients with confirmed primary colorectal carcinoma. INTERVENTIONS: Computed tomography during arterial portography (CT-AP), percutaneous ultrasonography (US), operative palpation and examination of the liver, operative US, and computed tomography (CT) follow-up 6-12 months postoperatively. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive and negative predictive value, and accuracy. RESULTS: Overall accuracy was worst for CT during portography, because of the diagnosis of many false positive lesions. Exploration and palpation of the liver had the highest sensitivity (83%) and specificity (100%), and operative US did not give any useful additional information. CONCLUSIONS: Preoperative percutaneous US is recommended as the best non-invasive screening test; otherwise careful inspection and palpation during operation are sufficient for the evaluation of the liver during primary resection for colorectal carcinoma.

Colonic Neoplasms↗
PubMed1995

[Ultrasound involvement of the spleen in non-Hodgkin's lymphomas].

UNLABELLED: Between 1980 and 1993, 680 patients with malignant lymphoma were referred for abdominal sonography as a part of staging. In 67 (9.8%) individuals with non-Hodgkin's lymphoma (NHL) sonography showed different degrees of lesions of the spleen. Splenic involvement was confirmed by histological examination (n = 5) and by clinical (n = 67) and sonographic follow-up examination (n = 56). 38 patients had low-grade (lg NHL), and 29 had high-grade non-Hodgkin's lymphoma (hg NHL). Four different sonographic patterns were found: diffuse infiltration (n = 20; 29.9%), small nodular lesions (n = 25; 37.3%), large nodular lesions (n = 20; 29.9%), and "bulky" disease (n = 2; 2.9%). All hg NHL exhibited focal lesions, which were large nodular in 15 out of 29 patients. In lg NHL small nodular and diffuse destruction of the splenic tissue texture were seen in 35 out of 38. CONCLUSION: Different texture patterns of the spleen can be found in patients with non-Hodgkin's lymphoma and splenic involvement with different lymphomas tending to exhibit different echomorphological infiltration patterns.

Adolescent↗
PubMed1995

[Ultrasound assessment of extranodal abdominal lymphoma involvement: an overview].

The abdominal sonograms of 680 patients with malignant non-Hodgkin's lymphomas (NHL) and Hodgkin's lymphomas (HD) were reviewed. An involvement in the spleen (n = 101), liver (n = 47), gastrointestinal tract (n = 70), kidney (n = 17), and various other organs (n = 19) could be demonstrated on ultrasound. Lesions were confirmed by histology (n = 117), sonographic (n = 141) and clinical follow-up. The different sonographic features of lymphomatous infiltrates in different extranodal sites are described, and possible correlations between lymphoma subtypes and sonographic texture characteristics are discussed. In cases with splenic and liver involvement, lymphoma subtypes had different patterns. A predominantly diffuse or small nodular infiltration was found in NHL of low-grade malignancy, and large nodular lesions were found to be more typical in high-grade NHL. The ultrasound findings basically do not allow a specific diagnosis and even may resemble a variety of malignant and non-malignant diseases other than lymphomas.

Abdominal Neoplasms↗
PubMed1994

Color Doppler imaging of focal splenic masses.

UNLABELLED: We report the sonographic findings in 43 patients with focal splenic masses. A differential diagnosis of splenic tumors was attempted on the basis of echotexture, size, vascularity and patterns of blood flow within and around tumors on color Doppler sonography. Using the surrounding splenic tissue as an in vivo reference, markedly hypervascular (n = 3), hypervascular (n = 2), isovascular (n = 4), hypovascular (n = 3), and avascular (n = 31) tumors could be differentiated. The final diagnoses were splenic infarction (n = 13), splenic rupture (n = 9), splenic metastasis (n = 7), splenic lymphoma (n = 3), splenic abscess (n = 4), hemangioma (n = 3), splenic cyst (n = 3) and splenoma (n = 1). In 17 cases (40%) color Doppler provides no further information for diagnosis, color Doppler was helpful in 21 patients (49%) and in four (9%) cases, Doppler sonography detects unexpected flow phenomena and was necessary for final diagnosis and treatment. In one patient (2%) sonographic diagnosis was incorrect. CONCLUSION: Characteristic patterns of blood flow were seen in different splenic tumors and can, therefore, aid in the differential diagnosis of focal splenic lesions, and identify patients at risk for serious complications.

Abscess↗
PubMed1994

Renal artery stenosis: grading with image-directed Doppler US evaluation of renal resistive index.

PURPOSE: To determine the role of intrarenal Doppler ultrasound (US) in detection of moderate to severe (> 50%) renal artery stenosis (RAS). MATERIALS AND METHODS: In 72 patients, 142 kidneys were examined with conventional angiography and color duplex US. Renal size, mean intrarenal-arterial resistive index (RI), and difference of mean RIs between both kidneys (delta RI) were determined and compared with severity of RAS as determined with quantitative angiography. RESULTS: In 32 patients, angiography showed mild RAS < or = 50% in 13, moderate RAS in 10, and severe RAS in nine. Both renal size and mean RI values were decreased significantly (P < .001) only for severe RAS compared with values in 40 control subjects. For delta RI, no significant difference was noted between controls and patients with mild RAS; highly significant differences, however, were noted for both moderate and severe RAS (P < .001). Sensitivity and specificity of a cutoff delta RI of > 5% were 82% and 92% for RAS > 50% and 100% and 94% for moderate RAS and RAS > 60%. CONCLUSION: Color Doppler US and analysis of intrarenal Doppler spectra are recommended as a useful method for noninvasive diagnosis and grading of RAS. In bilateral RAS > 50%, however, calculation of delta RI is potentially biased by undergrading of stenosis.

Angiography↗
PubMed1994

Adrenal pheochromocytomas: a broad spectrum of sonographic presentation.

Sonographic findings in 19 patients with proved adrenal pheochromocytomas observed over a 10 year period were evaluated retrospectively. Adrenal tumors were analyzed by number, size, echogenicity, internal echogenicity, and biologic behavior. There were 16 benign and 3 malignant pheochromocytomas, all of which were well marginated or encapsulated and ranged from 1.4 to 11 cm in greatest diameter (mean, 4.8 +/- 2.2 cm). A broad spectrum of sonographic appearances has been noted, including purely solid tumors (68%), complex masses (16%), and cystic lesions (16%). Compared with renal parenchyma as a reference tissue, 10 (77%) of 13 solid pheochromocytomas were isoechoic or hypoechoic, whereas three (23%) were hyperechoic. Six (46%) of the solid tumors were homogeneously echogenic, and seven (54%) were heterogeneous. Ultrasonic discrimination between benign and malignant pheochromocytoma on the basis of acoustic features alone has proved impossible. Abdominal sonography, however, provided evidence of malignancy in all three patients with malignant tumors by disclosing regional or distant metastases. In conclusion, rather than showing a specific uniform ultrasonographic appearance, pheochromocytoma is associated with a broad spectrum of possible sonographic presentations.

Adrenal Gland Neoplasms↗
PubMed1994

[Lymphoma infiltration of the liver: spectrum of ultrasound characteristics in 47 patients].

Between 1980 and 1993, 680 patients with malignant lymphoma were referred for abdominal sonography as a part of initial staging. In 53 patients intrahepatic abnormalities suspected for lymphoma involvement were detected. 6 of these had metastases of lung cancer (n = 4) or microabscesses (n = 2). Sonographic findings of 47 patients with hepatic lymphoma were reviewed. Hepatic lymphoma was confirmed by histologic examination (n = 23) and sonographic/clinical follow-up (n = 24). 12 patients had Hodgkin's disease, 18 high-grade NHL, and 17 low-grade NHL. Lesions were hypoechoic in all cases. Five different sonographic patterns were found: small nodular lesions (n = 28; 60%), large nodular lesions (n = 14; 30%), bulky disease (n = 2; 4%) and diffuse involvement (n = 2; 4%). One patient (2%) had lymphomatous involvement which surrounded the portal vessels. High-grade NHL preferred patterns of large nodular or bulky diseases (9 of 17 patients). Small lesions were found to be more typical in low-grade NHL (13 of 18 patients), and Hodgkin's disease (9 of 12 patients).

Adolescent↗
PubMed1994

[Focal necrotising vasculitis of the testis. Testicular manifestations of immunologic diseases in differential diagnosis of testicular cancer].

We report on the case of a 31-year-old male patient with focal testicular vasculitis as the only clinical manifestation of endangiitis obliterans (Winiwarter-Buerger disease), who presented with acute scrotal pain and swelling suggestive of a testicular tumor. Doppler sonography revealed significantly increased vascularization at the borders of the lesion, which rather indicated a vascular process; however, the presence of solid areas meant that the possibility of testicular cancer could not be excluded. Left inguinal orchiectomy was performed. The surgical specimen revealed histological patterns compatible with endangiitis obliterans; Raynaud phenomenon was the only sign of systemic disease, and no other organs were found to be affected. Despite the high sensitivity and specificity of ultrasound/Doppler sonography, in the differential diagnosis of an unexplained testicular mass surgical exploration is still mandatory. The different types of focal vasculitis are described and discussed with reference to the literature.

Adult↗